I am rebuilding a 1975 and looking for more performance. I have a good manifold, carb, inginition so looking for a long block. This is not anything special, keep up with neighbor mustangs, make so nice noise. I have found
Blueprint Motor, 373 Hp, 400 fl/lb Roller cam, hypertecic pistons, 2 bolt main.

Other suggestions??
Thanks

 

Budget
Rear axle ratio
Manual, auto?
Newer mustangs are pretty fast these days, trying to keep up can cost $
Is a mid 13 second car enough? 12s?
Take into account say a 400hp engine in a dyno cel may make 50hp less in a car.

Imo if you went the BP route Id get a mild 400ci engine. Big torque, great manners, no need for high rpm to have fun the engine isnt working hard. Not too much $ and youll never want a 350 again.

 

Having driven both a 327 Corvette and the 427 Corvette of the same year I can clearly tell you that there is "No Replacement for Displacement". The biggest problems you might run into are related to How Much can Your Corvette handle?

I currently have a 1968 C3 with its 427 and I love the torque as there is nothing like putting it 4th gear at 25 mph and stomping on it. My C3 was built for a high horsepower Big Block and it has the necessary parts to keep it all together. Since your car was not offered with the BB engines I would venture it would be a crowded engine compartment.

Lots of people want more HP with the 1972 and later Corvettes as the engines were being strangled by the new emissions laws coming into affect. You don't mention where you are so I assume that there are no emissions laws where you live. Here in Virginia you could get antique plates but those limit when and where you can use YOUR Corvette. I keep mine road legal so I can drive them any time I want, this means you have to meet the emissions numbers if you are going to drive it regularly. This would require you to have a catalytic converter and all the other parts needed to make the engine run "lean and clean". My 427 sports a Holley Sniper Stealth 4150 EFI system and my car easily meets the requirements for 1968 even without the catalytic converters required later on. My car goes through the annual safety inspections here in Virginia and is kept road worthy.

I rebuilt my 427 into L88 Clone engine and now the Corvette can only be driven when the roads are dry. In any rain the car will slide into the left lane every time I change a gear. When I put better tires on the Corvette suddenly the extra traction started to break parts in the drive line. I am looking to make the Corvette more drive able by installing a modern EFI system on it. A better tire will be found but not in the 15" size, it looks like the 18" tires have a lot of choices.

Don't forget that it takes DEEP pockets to make any serious Horsepower. I would make it work as well as you can and enjoy the Corvette for what it is. I spent over $10k on my engine when I built it and that was a while back. Small Blocks are easier to work on and cheaper than the big blocks are. A lot of folks like the newer LS engines for their older Corvettes. It is a lot of work and requires a good shop who knows what they are doing. Some of these newer aluminum LS engines would be the right way to go to have modern performance and the reliability of the newer engine.

Rebuilding your engine might be the least expensive way to go and end up with a great engine if you put the right parts into it. I would give it some serious consideration, if you haven't done this yet find a local speed shop and talk to them. I built mine with a mechanic who owned a local speed shop. I bought the parts and he and I would assemble them. I learned how to build a 427 and he sold a bunch of copies of my engine.

 

McCloskey makes a wise point that I think is often not considered when thinking of putting big torque / HP in a C3. Can the tires handle it? Can the driveline handle it?

The first thing to consider is if the tires / rubber on the road will handle big torque, i.e. or will they just spin. For my 77, when I decided to replace the built 350 I did have in the car with a big inch small block, I considered everything up to past a 427. I would have loved to build a 427 small block, just because of the number "427". But, after much research and forum reads by multiple posters, I decided on a 406. For me, I like my 15 inch wheels, which means I am stuck with limited tire options. I also like the look of the wheel wells being filled, so even the 60 size tires don't work for me. I have 70 size Coopers. They ride much better, and fill the wheel wells perfectly as they are the same diameter (27 inch) as the original tires. SO.......with that limitation, why go past 406?

Secondly, the truth is going bigger in a small block starts to impose compromises because of the bore limitations and the stroke limitations. It certainly can be done, as many have built 434 and bigger into a small block...BUT, the clearances are really tight, and I believe you start to get to the point you have an engine that will simply not go the distance. I came to the final conclusion that a 406 is as big as I need, given the tires I am willing to run, and without long term wear issues and reliability issues. I will also add that the bigger the displacement, the more money it cost. A 427 requires more machining than a 406. Also, for those interested, I started with a Dart SHP block. The engine cost me over $10K to have built, using all the best components.

Otherwise, to the OP, there are lots of options for a long block, with very reliable 350 engines built by Blueprints, and others, and going up from there 383, 406, etc. Small blocks will be alot easier as well because they will fit with most of the parts you already have. I considered a 427 big block, but there are lots of parts that would have to be changed, making it even more expensive. Its not a drop in like a small block would be.....possible of course, as C3 Corvettes were built with big blocks, but more complicated of a conversion.

 

that 373hp BP ReMan motor, like most of their sbc's now, is already bored out 0.060" look on BP website that's plain as day. No one can ever bore it past that even if you could find a piston except Hi-$ customs. And at Sixty over, it's likely 880 blocks' walls are paper thin and just lookin for trouble. not for me. I know a few guys I might recommend it to; they're not exactly friends.

Spend another grand & buy ALL BRAND NEW GM crate w/ roller cam , 4 bolt main, Vortecs, roller lifters & similar hp/tq. ~ $3800 delivered NEW !
https://www.summitracing.com/parts/nal-19367080 also $250 rebate !

pace has an All New GM crate like above but with the LT4 Hot Cam easy 390-400hp ~ $3950 delivered NEW ! maybe a rebate on this one as well !
https://paceperformance.com/Small-Bl...691672-4X.html